ABL - ABL protooncogene has tyrosine kinase activity. In chronic myeloid leukemia and certain acute leukemias, the ABL gene is translocated from its normal abode on chromosome 9 to chromosome 22, where it fuses with part of the breakpoint cluster region (BCR) gene. The BCR-ABL hybrid gene has potent tyrosine kinase activity and it activates several growth stimulating pathways.

4) Nuclear Regulatory Proteins - Growth autonomy may occur as a consequence of mutations affecting genes that regulate transcription of DNA. A host of oncoproteins, including products of the MYC, MYB, JUN, FOS, and REL oncogenes, localised on the nucleus and there mutant varitey may lead to sustained proliferation of cells.

5) Cell-Cycle Regulators – cyclin, CDK and CDK inhibitors

Designer drugs- why do we need to know about the growth signalling pathway

Cetuximab: antibody against EGFR

Imatinib mesylate: inhibitor of Abr-bcl chimeric protein which acts as a tyrosine kinase; DOC in CML

p53 is the central monitor of stress in the cell and can be activated by anoxia, inappropriate oncogene signaling, or DNA damage. Activated p53 controls the expression and activity of genes involved in cell cycle arrest, DNA repair, cellular senescence, and apoptosis

Apoptosis : There is activation of a proteolytic cascade of caspases that destroys the balance between pro-apoptotic (e.g., BAX, BAK) and anti-apoptotic molecules (BCL2, BCL-XL)

p53 can be incapacitated by binding to proteins encoded by oncogenic DNA viruses like HPV, and possibly EBV and HBV

Telomerase and limitless replicative potential of cancer cell

In normal cells, which lack expression of telomerase, the shortened telomeres generated by cell division eventually activate cell cycle checkpoints, leading to senescence and placing a limit on the number of divisions a cell may undergo

Anti- angiogenic protein produced by VHL gene( Von Hippel Lindau): VHL acts as a tumor suppressor gene, and its is associated with cell cancers, pheochromocytomas, hemangiomas of the CNS and retina (VHL syndrome).